Sealing rings for ventilation ducts



FIG. 1 is a perspective view of a sealing ring according to a first embodiment of the new design, as seen obliquely from one side.

FIG. 2 is a cross-sectional view of the sealing ring of FIG. 1 shown on an enlarged scale.

FIG. 3 is a perspective view of a sealing ring according to a second embodiment of the new design, as seen obliquely from one side; and,

FIG. 4 is a cross-sectional view of the sealing ring of FIG. 3 shown on an enlarged scale. 

The ornamental design for sealing rings for ventilation ducts, as shown. 